Children given more fast food meals will grow up to have a lower IQ than those regularly given freshly-cooked meals, a study has revealed.

According to new research, childhood nutrition has long lasting effects on IQ, even after previous intelligence and socio-economic status are taken into account.

The study at Goldsmiths, University of London, examined whether the type of children's daily main meal had an impact on their cognitive ability and growth.

The results were based on a sample of 4,000 Scottish children aged three to five and found parents of higher socio-economic status reported to give their children meals prepared with fresh ingredients more often, which positively affected their IQ.

Lower socio-economic status was linked to more children having fast food, which led to lower intelligence.

Dr Sophie von Stumm, from the department of psychology at Goldsmiths, said: "It's common-sense that the type of food we eat will affect brain development, but previous research has only looked at the effects of specific food groups on children's IQ rather than at generic types of meals.

"This research will go some way to providing hard evidence to support the various high-profile campaigns aimed at reducing the amount of fast food consumed by children in the UK."

Dr von Stumm said the findings highlighted that differences in children's meals were also a social problem.

She said: "Mothers and fathers from less privileged backgrounds often have less time to prepare a freshly cooked meal from scratch for their children.

"These children score lower on intelligence tests and often struggle in school. Schools in less privileged areas must do even more to balance children's diet, so that they can achieve their cognitive potential."